Research On Technology Of Ultra-wideband Pulse Generation

Ultra wideband pulse source technology is one of the core technologies in the field of carrier-free impulse ground penetrating radar.It has been widely used in ground penetrating radar,through-the-wall radar and landmine detecting system.However,the traditional pulse generation circuit has higher pulse tailing and cannot achieve implement low amplitude and narrow pulse width simultaneously,which limits its application.In this paper,the ultra-wideband pulse generation technology applied in penetration and detection is studied deeply,and good results have been obtained.Firstly,this paper studies the basic working principles of step recovery diode and avalanche transistor,and analyzes the relationship between the output pulse performance and the parameters of the semiconductor device.This paper also point out that the important parameters affecting the output pulse amplitude and tail of the avalanche transistor circuit are the resistance between the energy storage capacitor and the transistor base emitter and proposes that a method to optimize the resistance and capacitance sharpening between emitter and emitter is proposed,which effectively increases the amplitude of output pulse and reduces the trailing edge of pulse.Furthermore,this paper presents that key factors of influencing output pulse amplitude and edge conversion time in terms of studying deeply current active used step recovery diode.The nonlinear simulation model of SRD is established by simulation software,and the feasibility of the model is verified by simulation and experiment.The design method of multi-stage pulse shaping circuit is put forward.The formula of multi-stage circuit parameter design is deduced by theoretical calculation.The simulation and experiment are used to verify the consistency between the theoretical derivation and the actual testBased on above research achievements,a kind of monocyclic pulse signal source circuit is designed.And trailing of output pulse is decreased effectively by impedance matching and Schottky diodes with bidirectional conduction.Results of simulation and experimental research show that performances of the final output of the pulse signal have good coherence to performances of the expected of that.